1. Field of the Invention
The invention relates to a dental clamp and, more particularly, to a clamp for use with a rubber dam when it is desirable to isolate one or more teeth being treated.
2. Description of the Related Art
Certain dental operations, such as root canals, are performed with a flexible sheet, such as a rubber dam retained around the tooth, or in some cases several teeth, undergoing treatment. The dam isolates one or more teeth from the rest of the interior of the patient""s mouth and serves two functions. One, it prevents ingestion by the patient of medicine or other substances associated with the operation and, two, it inhibits the introduction of bacteria and other contaminants from the mouth into the operating theater around the tooth during the procedure. The dam comprises a flexible membrane retained in a frame. While the frame is placed outside the mouth, the membrane is flexible enough to extend inwardly of the patient""s mouth. In the case of a single treated tooth, a hole is punched in the membrane to accommodate the tooth and the dam is inserted over the tooth so that it is the only tooth exposed through the hole. A similar procedure is employed if more than one tooth is to be isolated.
A dental clamp is typically used to retain the rubber dam in proper position around the tooth. Dental clamps include a pair of laterally opposed jaws that are spring-biased to grip the tooth immediately above the gum line. The clamp typically attaches to the dam at the hole for positioning the dam around the tooth. The clamp is applied by spreading the jaws with a special forceps, positioning the clamp around the tooth, and carefully releasing the jaws when the clamp has been properly placed. The edges of the jaws may include serrations to facilitate gripping of the tooth or it may include a soft bumper to avoid damage to the surrounding gums.
FIG. 1 shows one embodiment of a tooth clamp according to the prior art. The tooth clamp comprises a resilient arcuate spring A which is attached at each end to jaws B. The jaws B are laterally opposed and define an intervening space C. The inwardly directed edge D of each jaw B is curved and may include serrations. The shape of the edge D is intended to correspond roughly with the arc of a tooth along the gum line.
Each jaw B is provided with an aperture F for insertion of a forceps, which is used to spread the jaws B apart for placement of the clamp around the tooth. Tabs E extend laterally from the outside edges of the jaws B. The tabs E are inserted into a hole in a rubber dam G to spread the hole open.
One of the problems with known clamps is that the spring force, and thus the force required to open the clamp, is very high, making the placement of the clamp on a tooth difficult. Also, such force may cause the device to bite into the gums if the placement is improper, or if the device is urged downwardly by the shape of the tooth. In addition, the clamp may slide off the tooth during a procedure, thus disrupting the treatment and permitting the introduction of contaminating substances to the operating theater.
These problems are solved by the present improvement in a dental clamp of the type for clamping a tooth and supporting a flexible sheet during a dental operation. Such a clamp typically has a resilient member connecting oppositely disposed jaws and biasing the jaws toward each other. Each jaw comprises a plate having an outward edge for engaging the flexible sheet and an inward edge that together with the opposing inward edge define a space between the jaws. The improvement lies in a plurality of resilient fingers extending from the inward edge of each plate and toward the oppositely disposed plate.
Preferably, the resilient fingers are arranged in a rank on each jaw. In one aspect of the invention, the resilient fingers extend slightly away from the resilient member. In another aspect of the invention, each finger has a crimp to facilitate resiliency. Preferably, the ends of the fingers are arranged to define a curve roughly approximating the curvature of a tooth. The jaws can each incorporate an additional tab to further engage and hold the flexible sheet.